Conventionally, there is a printing system in which a host computer and a printer are connected to print a document prepared by the host computer through the printer. The printing system of this type outputs a character code obtained by encoding a character string constituting a document from the host computer to the printer, and designates a font to be used and executes printing.
In recent years, the number of computers mixing and treating characters of languages has gradually been increased with globalization. The computers use Unicode as a character code in many cases. The Unicode has more than one million code points which are suitable for languages in the world. In the case of addition of code representation including a variant character selector (IVS) for identifying variant characters to be characters which have the same meaning and pronunciation as a standard character styles and written differently, the number of character codes possessed by the Unicode is increased further enormously. However, no font covers all character forms of the Unicode having the enormous number of character codes.
In respect of a spool size or printing quality, it is desirable to edit a document by using a font in a host computer in document preparation and to print the document by using a font in a printer in printing. However, the number of types of fonts which can be printed by the printer is generally smaller than that of fonts which can be used in the document preparation of the host computer. In some cases, accordingly, a document prepared by the host computer includes a character having a font of a type which cannot be printed by the printer. In these cases, there is a problem in that a printed document has garbage characters when the host computer designates a font which is not present at the printer side, thereby executing the printing.
On the other hand, there is proposed the technique for enabling printing also in the case in which a font designated by a host computer is not present in a printer (for example, see Patent Documents 1 and 2).
Referring to the technique described in the Patent Document 1, it is decided whether a printer has an in-host font designated for a character to be printed. If the designated in-host font is not present in the printer, a font in the printer is specified as an alternative font. When the alternative font is used, there is calculated a position of each character if the in-host font used and information thus obtained is output to the printer. The printer determines a arrangement position to an image of each font in accordance with the information, thereby guaranteeing a format of a whole document.
Referring to the technique described in the Patent Document 2, moreover, a host computer communicates with a printer to acquire an in-printer font which can be used in the printer. Then, the in-printer font thus acquired is compared with an in-host font which can be used in the host computer and at least a part of the in-host fonts are replaced by optional in-printer fonts and are thus set, and the replaced fonts are also set to the printer. As compared with the case in which data on the in-host font is expanded at the host computer side and a character string is transmitted as image data to the printer side to execute printing, consequently, it is possible to reduce a data volume to be transmitted from the host computer to the printer, thereby increasing a data transfer rate.
Patent Document 1: Japanese Laid-Open Patent Publication No. 1994-325035
Patent Document 2: Japanese Laid-Open Patent Publication No. 2000-172472